Sarcosinate shampoo

ABSTRACT

A homogeneous aqueous shampoo composition comprises by weight (a) 6-15% of an N-acyl sarcosinate, (b) 2-8% of either an alkyl sulphate or an alkyl ethenoxy ether sulphate containing 1-5 ethylene oxide units per molecule, (c) 3-8% of a mixture of acyl mono- and di-ethanolamides in a weight ratio of 2:1 to 1:2, and (d) 3-12% of ethanol, glycerol, or propylene glycol, the weight ratio of (a) to (b) being 3:2 to 3:1 and the pH of the solution being 6-7.5.  The composition generally also contains (e) 0.3-2% of an amino polycarboxylate sequestrant such as a hydroxyethyl ethylenediamine triacetate, a nitrilotriacetate, a 2-hydroxyethylimino diacetate, a diethylene triamine pentacetate, a 1:2-diamino-cyclohexane tetracetate or, most suitably, an ethylene diamine tetracetate; the cations present in components (a), (b) and (e) are sodium, potassium, ammonium or triethanolammonium. The acyl and alkyl groups present in components (a), (b) and (c) contain 10-18 carbon atoms and in at least 45% of the groups in each case 12 carbon atoms; preferably these acyl and alkyl groups substantially all contain only 12 carbon atoms.  The composition may also include up to 0.5% of colouring, up to 2% methyl cellulose or sodium carboxymethylcellulose, up to 1% perfume, up to 0.5% ammonium or sodium sulphite (colour stabilizer), up to 0.01% phenyl mercuric acetate (preservative), up to 5% ethylene glycol distearate (opacifier) and up to 0.2% of an ultraviolet absorbent or antioxidant.  The pH of the composition may be adjusted with citric acid or triethanolamine.

United States Patent 3,085,067 SARCOSINATE SHAMPOG John A. Anderson,pringfieid Township, Harniiton County, Qhio, assignor to The Procter &Gamble Company, Cincinnati, Ohio, a corporation of Qhio No Drawing.Filed Feb. 10, 1960, Ser. No. 7,779 4 Qlairns. (Cl. 252-453) Thisinvention relates to a sarcosinate-based shampoo formulated from acombination of ingredients so selected and so proportioned thatoutstanding lathering, cleaning, hair conditioning and hard waterresistance characteristics are obtained.

Most users ofchampoos have definite requirements with respect to theperformance characteristics of the products they use. A shampoo whichmerely cleans the hair is not necessarily a satisfactory product; it isoften said that a shampoo which cleans too well is unsatisfactory. Inaddition to cleaning adequately, the product must lather Well during theshampooing operations and must condition the hair, i.e. leave the hairin a soft, smooth, lustrous and easily manageable state. The shampoomust be mild and have sufficient resistance to hard water since hardwater may cause a reduction in lather and cleaning efiiciency and maycause an undesirable film formation on the hair. The use of softenedwater or special rinses are not satisfactory solutions to hard waterproblems for a commercially acceptable shampoo.

The chief problem in formulating a shampoo which has the combination ofthe requisite properties is that a particular ingredient which willimpart to the shampoo one or perhaps several of the requisite propertiesin an outstanding manner will adversely affect one or more of theremaining properties. For example, soap-based shampoos, in soft water,have excellent cleaning, lathering and hair conditioning properties;however, any hardness in water adversely affects the latheringcharacteristics and leaves the well known undesirable hard water soapcurd.

equestering and curd dispersing additives have improved soap shampoos tosome extent but the majority of successful shampoos are based on thosenon-soap synthetic detergents which lather and clean well in hard orsoft water. Such non-soap detergents, however, have the shortcoming ofcleaning so well thatthe natural oil of the hair, which naturallyconditions the hair, is removed leaving it harsh and unmanageable.

If the shampoo preparation is designed to preserve much of the naturaloil in the hair, the criticism can be voiced that it does an incompletecleaning job. Some shampoos attempt to solve this problem by using ahighly effective detergent with a hair conditioning agent which servesas a replacement for the oil removed from the hair. Examples of suchhair conditioning agents are polyglycols, fatty acid esters of glycols,natural or synthetic Waxes, and lanolin derivatives. Use of formulationscontaining excessive amounts of hair conditioning agents of the oilytype may cause the hair to have an unpleasant oily appearance and feel.Formulations containing certain hair conditioning agents suffer from theadditional difiiculty that the oily material inhibits sudsing of theshampoo. Most people have come to expect copious lather from theirshampoo and are dissatisfied if it is not formed.

It is an object of this invent-ion to provide a homogeneous shampoowhich is preferably substantially clear and which produces a copiouslather, effectively cleans the hair, and leaves the hair, after drying,in a soft, lustrons, easily manageable condition.

It is another object of this invention to provide a shampoo which hasthe above characteristics in hard as IWCH as soft water and which doesnot form an undesirable hard water precipitate.

It was found that these and other objects are obtained by providing ashampoo containing, as its essential ingredients in an aqueous vehicle,an N-acyl sa-rcosinate, an alkyl sulfate or an alkyl ethoxylated ethersulfate and a blend of acyl monoand diethanolamides. These ingredientsare so selected and so proportioned that a shampoo having .a highlysatisfactory balance of the requisite properties, enumerated above, isobtained. Minor amounts of a solvent should be included in the shampooto improve its physical characteristics and minor amounts of asequestrant can be included, if desired, for the same purpose ashereinafter more fully described. The pH of the shampoo should be in therange of 6 to 7.5 for optimum performance and physical characteristics.

The essential ingredients of the shampoo of this invention are definedin greater detail as follows: N-acyl sarcosinates are the salts ofcondensation products of fatty acids with sarcosine, RCON(CH CH COOM;alkyl sulfates are the salts of sulfated fatty alcohols, R'OSO M; alkylethoxylated ether sulfates are mixtures of salts of sulfa-tedcondensation products of from 1 to 5 moles of ethylene oxide with onemole of fatty alcohol,

x ranging from 1 to 5 and preferably averaging about 3; acylmonoethanolamides are the condensation products of one mole of fattyacid with one mole of ethanolamine, RCONHCH CH OH; acyl diethanolamidesare the condensation products of one mole of fatty acid with two molesof ethanolarnine, RCON(CH CH OH) The acyl radicals (RC0) and alkylradicals (R') in the above ingredients preferably have a chain length of12 carbon atoms or are mixtures of radicals ranging in chain length from10 to 18 carbon atoms such that at least about 45% of the radicals inany given ingredient con rain 12 carbon atoms. Suitable mixtures areavailable from natural or synthetic sources. Coconut oil (or other oilfrom the coconut oil group, e.g. palm kernel or babassu oil) is a sourcefor coconut type fatty alcohol and coconut type fatty acids which havechain lengths suitable for the ingredients used in the shampoo of thisinvention. For example the middle cut obtained in the distillation ofcoconut fatty alcohol having the following composition: 2%C 66%C 23%-Cand 9%C alcohols, is a desirable source for alkyl radicals in the aboveingredients; coconut fatty acids having the same chain lengthcomposition are a desirable source of acyl radicals. Whole cut coconutfatty acids can also be used as a source of acyl radicals; an example ofthe chain length distribution of such material is C 15%, C12-50%,C1417%, C16-7% and C ll%.

The cation M in the above ingredients can be sodium, potassium, ammoniumor triethanolarnrnonium. The latter is preferred because of the somewhatgreater solubility of the triethanolammonium salts.

The chief ingredient of the shampoos of this invention is acylsarcosinate. This synthetic detergent has excellent lathering andcleansing characteristics and at the same time has outstanding hairconditioning characteristics. This latter characteristic is a result ofa very thin conditioning film of acyl sarcosinate which is formed aroundeach strand of hair after the shampooing operation and during rinsing.This film is similar to the thin conditioning fihn formed by soap insoft Water. However, the sarcosinate conditioning film formed around thehairstrands in hard water shampooing is just as satisfactory as thatformed in soft water whereas hard water soap film is highly undesirable.

Although the acyl sarcosinate lathers well and cleans well, it was foundthat it should be supplemented by an alkyl sulfate or an alkylethoxylated ether sulfate in certain proportions in order to provide, inthe shampoo, a mixture of components which provides the large amount oflather which is desired by the user. These sulfated detergents bythemselves do not have the outstanding conditioning properties of theacyl sarcosinate.

The acyl sarcosinate is used in the amount of about 6% to about of theshampo composition. (-All percentages and ratios used herein are byweight.) The sulfated detergent is used in the amount of about 2% toabout 8% of the shampoo composition. Since the acyl sarcosinate shouldpredominate in order to obtain the desired hair conditioningcharacteristics, the ratio of sarcosinate to sulfated detergent shouldbe in the range of about 3:2 to about 3:1. The above percentages arefixed on the lower side to provide the user with a sufficient amount ofdetergent for satisfactory results with respect to the volume ofdetergent solution customarily used in shampooing. They are fixed on theupper side by solubility of the various ingredients in the shampooformulation which should not be exceeded if a substantially clearhomogeneous product is to be obtained and maintained at ordinarytemperatures.

\Although the acyl sarcosinate and sulfated detergent ingredients in theproportions described above provide excellent lathering characteristics,the shampoo, without certain additional lather builders does not havethe particular lathering characteristics required by the user. Lather isimportant to the shampoo user because he or she uses it as a measure ofthe correct amount of shampoo needed to wash the hair thereby avoidingboth linsuilicient cleaning and wasted product. Moreover, shampoo usershave come to associate lather with detergent efficiency. The shampoouser desires a large amount of lather which is stable (persiststhroughout the shampooing operation) and which has good texture, i.e.body and lubricity. While the mixture of acyl sarcosinate and sulfateddetergent provides an ample volume of lather, lather builders should beused with the mixture to increase the stability of and improve thetexture of the lather.

Acyl monoethanolamides are outstanding lather builders for the mixtureof sarcosinate and sulfated deter-gent described above but their use asthe sole builders detracts undesirably from the hair conditioningproperties of the acyl sarcosinate. Moreover, the solubility of the acylmonoethanolamide is somewhat limited making it more difiicult to obtaina homogeneous product than if the more soluble acyl diethanolamides areused. Acyl diethanolamides have limited lather building properties anddo not detract from the hair conditioning properties of the acylsarcosinate; however acyl diethanolamides do not provide a satisfactorylather building action for the mixture of acyl sarcosinate and sulfateddetergent. Thus the use of either an acyl monoethanolamide or an acyldiethanolamide as the sole lather builder provides unsatisfactorycharacteristics. in either hair conditioning or lathering of theresultant shampoo.

Surprisingly, it was found that a careful blend of acyl monoanddi-ethanolamides used in conjunction with the combination of acylsarcosinate and sulfated detergent described above provides ahomogeneous shampoo having outstanding lathering, cleaning and hairconditioning characteristics in either hard or soft water. It was foundthat the ratio of the acyl monoethanolamide to the acyl diethanolamideshould be in the range of about 2:1 to about 1:2 and the total amount ofthe two amides should be from about 3% to about 8% of the shampoocomposition.

In order to ensure that the shampoo composition containing the aboveessential ingredients is homogeneous and remains so, a solvent, eitherethanol, glycerin or propylene glycol, should be included in theshampoo. The solvent also acts to maintain the clarity of the preferredsubstantially clear shampoo product. The solvent is especial- 1ydesirable to ensure that the shampoo formulation will recover to asubstantially clear homogeneous product after being rendered nonhomogeneous and/or cloudy at low temperatures which might be encounteredin storage or transit. The ethanol, glycerin or propylene glycol is usedin an amount of about 3% to about 12% of the shampoo composition.Solvents other than ethanol, glycerin or propylene glycol, such asmethanol, isopropanol, or ethylene glycol, are not satisfactory becauseof toxicity and/or odor problems. Ethanol is the preferred solvent.

It is preferable to include in the shampoo compositions of thisinvention a sequestrant to ensure that the solution of ingredients is asclear as possible. To this end about 0.3% to about 2% of an aminopolycarboxylate sequestrant is included. Examples of this type ofsequestrant are ethylene diamine tetra acetates, hydroxyethyl ethylenediamine triacetates, nitrilo triacetates, 2 hydroxyethyl iminodi'acetates, diethylenetriamine penta acetates, and 1,2 diaminocyclohexane tetra acetates. These sequestrants are used in the form oftheir full or partial sodium, potassium, ammonium or triethanolammoniumsalts so as to conform with the pH range of the shampoo as hereinafterdiscussed. The exact form of the sequestrant will depend on theparticular compound and cation used. Sequestrants also tend to increasethe volume of lather of the shampoo. Ethylene diamine tetra acetate isthe preferred sequestrant.

The pH of the shampoo should be in the range of about 6 to about 7.5. AtpHs less than about 6 the clarity of the shampoo tends to be impaired.At pHs greater than about 7.5 the lathering characteristics of theshampoo are reduced. The pH of the shampoo can be adjusted if necessarywith any of the usual :acidic or basic agents such as citric acid ortriet'hanolamine.

Various minor ingredients customarily used in shampoos can be added tothe composition of the invention to make it more attractive inappearance or use, but are not necessary. Examples of such minoringredients are: up to about 0.5% color; up to about 2% thickening agentsuch as methyl cellulose or. sodium carboxymethylcellulose; up to about1% perfume; up to about 0.5% of a color stabilizer such as ammonium orsodium sulfite; up to about 0.01% of a preservative such as phenylmercuric acetate; up to about 0.2% of an ultraviolet absorbent or anantioxidant. Although the shampoo compositions of this inventionpreferably are substantially clear, up to about 5% of an opacifier, suchas ethylene glycoldistearate, can be added if an opaque product isdesired.

The shampoo of this invention is illustrated by the following example.

Example A shampoo composition was obtained by uniformly mixing togetherthe following ingredients:

4% triethanolamine salt of the sulfated condensation product of 3 molesof ethylene oxide and one mole of coconut oil fatty alcohol having thefollowing chain length distribution: 2% C 66% C 23% C and 9% C 10%triethanolamine N-acyl sarcosinate, the acyl radicals being derived fromcoconut oil fatty acids and having the following chain lengthdistribution: 10% C C12, C14! C18 and C13 3% monoethanolamine of coconutoil fatty acids having the following chain length distribution: 16% CC12, C14, C16 :and C13 3% diethanolamide of coconut oil fatty acidshaving the following chain length distribution: 16% C 48% C12, C14, C16and C18 0.65% ethylenediamine tetraacetic acid (as its partialtriethanolammonium salt) 7% ethanol 0.75% methyl cellulose, a 2%solution of which has a viscosity of 4000 cps. at 68 F. and a gel pointof F.

0.15% sodium sulfite 0.007% phenyl mercuric acetate 0.75% perfumeBalance water.

The pH of the shampoo was 6.7.

The shampoo was a clear, white, homogeneous liquid. When used on uncleanhuman hair with both hard and soft water, copious lather having :a goodtexture quickly formed and persisted during the shampooing operation.There was no evidence of any adverse effects with the use of hard water,even that having a hardness of 12 grains per gallon. The product and itslather rinsed easily and substantially completely away leaving the hair,after drying, in a soft, lustrous state which was easy to comb andmanage. In the opinion of a number of experienced beauticians whoperformed the shampooing operation with the composition of this example,and a number of persons whose hair had been shampooed with thecomposition, the hair conditioning properties of the shampoo wereexcellent and were at least equal to the conditioning properties of ahigh quality soft-water soap shampoo.

Propylene glycol or glycerin can be substituted in an equal amount forethanol in the above example with substantially equal results.

The sodium, potassium or ammonium salts of the sulfated condensationproduct and of the N-acyl sarcosinate described in the above example canbe substituted in equivalent amounts for the correspondingtriethanolamine salts used in the composition of the example withsubstantially equal results.

An equivalent amount of triethanolamine, sodium, ammonium or potassiumlauryl sulfate can be substituted for the sulfated condensation productin the above example with substantially equal results. Alkyl ethoxylatedether sulfates are preferred over the corresponding alkyl sulfatesbecause the former have slightly greater solubilities and greatermildness.

An equivalent amount of a triethanolamine or sodium salt of hydroxyethylethylene diamine triacetic acid or nitrilo triacetic acid can besubstituted for the ethylene diamine tetra acetic acid in the aboveexample with substantially equal results.

What is claimed is:

1. A clear homogeneous, liquid shampoo which will produce copious stablelather having good texture; effectively clean the hair; and leave thehair in a soft, lustrous, easily manageable condition even when used inhard water, consisting essentially of an aqueous solution of (a) about6% to about 15% of an N-acyl sarcosinate, (b) about 2% to about 8% of anon-soap detergent selected from the group consisting of alkyl sulfatesand alkyl ethoxylated ether sulfates containing one to five ethyleneoxide units per molecule, about 3% to about 8% of a mixture of an acylmonoethanolamide and an acyl diethanolamide, the ratio of said amidesbeing in the range of about 2:1 to about 1:2, (d) about 3% to about 12%of a solvent selected from the group consisting of ethanol, glycerin andpropylene glycol, the ratio of (a) to (b) a being in the range of about3:2 to about 3:1, the acyl and alkyl groups in the ingredients rangingfrom 10 to 18 carbon atoms in chain length with at least 45% of the saidgroups in each ingredient being 12 carbon atoms in chain length, thecations of the said sarcosinate and the said detergent being selectedfrom the group consisting of sodium, potassium, ammonium andtriethanolammonium, the pH of said solution being from about 6 to about7.5, the percentages and ratios being by weight.

2. The shampoo composition of claim 1 which includes as an additionalingredient about 0.3% to about 2% of an amino polycarboxyl-atesequestrant selected from the group consisting of ethylene diaminetetraacetates, hydroxy ethyl ethylene diamine triacetates, nitrilotriacetates, 2 hydroxyethyl imino diacetates, diethylenetriamine pentaacetates and 1,2 diamino cyclohex-ane tetra acetates.

3. A clear, homogeneous, liquid shampoo which will produce copiousstable lather having good texture; effectively clean the hair; and leavethe hair in a soft, lustrous, easily manageable condition even when usedin hard water, consisting essentially of an aqueous solution of (a)about 6% to about 15% of a triethanolamine N-acyl sarcosinate, (b) about2% to about 8% of triethanolamine alkyl ethoxylated ether sulfatescontaining an average of three ethylene oxide units per molecule, (c)about 3% to about 8% of a mixture of an acyl monoethanolarnide and anacyl diethanolamide, the ratio of said amides being in the range ofabout 2:1 to about 1:2, (d) about 3% to about 12% ethanol, (e) about0.3% to about 2% of an ethylenediamine tetra acetate, the ratio of (a)to (1)) being in the range of about 3 :2 to about 3: 1, the acyl andalkyl groups in the ingredients ranging from 10 to 18 carbon atoms inchain length with at least 45 of the said groups in each ingredientbeing 12 carbon atoms in chain length, the pH of said solution beingfrom 6 to 7.5, the percentages and ratios being by weight.

4. A clear, homogeneous, liquid shampoo which will produce copiousstable lather having good texture; effectively clean the hair; and leavethe hair in a soft, lustrous, easily manageable condition even when usedin hard water, consisting essentially of an aqueous solution of about10% of a triethanolamine N-acyl sarcosinate, about 4% of triethanolaminealkyl ethoxylated ether sulfates contraining an average of threeethylene oxide units per molecule, about 3% of an acylmonoeth'anolamide, about 3% of an acyl diethanolamide, about 0.65% oftriethanolamine ethylene diamine tetraacetate, about 7% ethanol, theacyl and alkyl groups in the ingredients ranging from 10 to 18 carbonatoms in chain length with at least 45% of the said groups in eachingredient being 12 carbon atoms in chain length, said solution having apH of about 6.7, said percentages being by weight.

References Cited in the file of this patent UNITED STATES PATENTS2,970,963 Walker et al. Feb. 7, 1961 OTHER REFERENCES Schwartz et al.:Surface Active Agents and Detergents, vol. 2, 1958, pp. 315-316.

Zussman et al.: Acylated Amino Acids in Shampoos, in Journal of theSociety of Cosmetic Chemists, vol. 6, #5, December 1955, pp. 407-415.

Harris: Shampoo Formulation, in the American Perfumer and Essential OilReview, December 1946, pp. 71.

Harris: Shampoo Formulation, in the American Perfumer and Essential OilReview, November 1946, pp. 54-56.

The Versenes, pub. by Bersworth Chemical Co., Technical Bulletin No. 2,1952, See. 'I, pp. 2 and 3, and Sec. II, pp. 10 and 11.

1. A CLEAR HOMOGENEOUS, LIQUID SHAMPOO WHICH WILL PRODUCE COPIOUS STABLELATHER HAVING GOOD TEXTURE; EFFECTIVELY CLEAN THE HAIR; AND LEAVE THEHAIR IN A SOFT, LUSTROUS, EASILY MANAGEABLE CONDITION EVEN WHEN USED INHARD WATER, CONSISTING ESSENTIALLY OF AN AQUEOUS SOLUTION OF (A) ABOUT6% TO ABOUT 15% OF AN N-ACYL SARCOSINATE, (B) ABOUT 2% TO ABOUT 8% OF ANON-SOAP DETERGENT SELECTED FROM THE GROUP CONSISTING OF ALKYL SULFATESAND ALKYL ETHOXYLATED ETHER SULFATES CONTAINING ONE TO FIVE ETHYLENEOXIDE UNITS PER MOLECULE, (C) ABOUT 3% TO ABOUT 8% OF A MIXTURE OF ANACYL MONOETHANOLAMIDE AND AN ACYL DIETHANOLAMIDE, THE RATIO OF SAIDAMIDES BEING IN THE RANGE OF ABOUT 2:1 TO ABOUT 1:2, (D) ABOUT 3% TOABOUT 12% OF A SOLVENT SELECTED FROM THE GROUP CONSISTING OF ETHANOL,GLYCERIN AND PROPYLENE GLYCOL, THE RATIO OF (A) TO (B) BEING IN THERANGE OF ABOUT 3:2 TO ABOUT 3:1, THE ACYL AND ALKYL GROUPS IN THEINGREDIENTS RANGING FROM 10 TO 18 CARBON ATOMS IN CHAIN LENGTH WITH ATLEAST 45% OF THE SAID GROUPS IN EACH INGREDIENT BEING 12 CARBON ATOMS INCHAIN LENGTH, THE CATIONS OF THE SAID SARCOSINATE AND THE SAID DETERGENTBEING SELECTED FROM THE GROUP CONSISTING OF SODIUM, POTASSIUM, AMMONIUMAND TRIETHANOLAMMONIUM, THE PH OF SAID SOLUTION BEING FROM ABOUT 6 TOABOUT 7.5, THE PERCENTAGES AND RATIOS BEING BY WEIGHT.